Use of a gas chromatography–mass spectrometry organic aerosol monitor for in-field detection of fine particulate organic compounds in source apportionment

Abstract

The identification of sources and secondary formation pathways leading to observed levels of PM (particulate matter with an aerodynmaic diameter <2.5 μm) is important in making regulatory decisions on pollution control. The use of organic marker compounds in this assessment has proven useful; however, data obtained on a daily, or longer, sampling schedule limit the value of the information because diurnal changes associated with emissions and secondary aerosol formation cannot be identified. A new instrument, the gas chromtography-mass spectrometry (GC-MS) organic aerosol monitor, allows for the determination on these compounds on an hourly averaged basis. The demonstrated potential value of hourly averaged data in a source apportionment analysis indicates that significant improvement in the data used for making regulatory decisions is possible.

Airborne and ground-based observations of ammonium-nitrate-dominated aerosols in a shallow boundary layer during intense winter pollution episodes in northern Utah

“…6a. The data of freshly emitted biomass burning aerosols shown in Cubison et al (2011) tended to have high f 60 (0.02 to 0.04) with relatively low f 44 (about 0.05) that changed to lower f 60 (< 0.02) and higher f 44 (0.15 to 0.23) as the aerosols aged. For the UWFPS study, however, f 60 was generally low and f 44 varied considerably.…”

“…Prior studies using an AMS instrument indicate that a potential marker of wood combustion is signalled at the massto-charge ratio (m/z) of 60, which is a major ion fragment present in spectra from the known biomass burning marker species, levoglucosan . The fraction of the organic mass spectrum that is at m/z 60 (termed f 60 ) is about 8 % in spectra from levoglucosan and is often significantly larger than the background value of 0.3 % (or 0.003) for air masses that are influenced by biomass burning (Cubison et al, 2011). During wintertime evenings, wood combustion is known to be a major contributor to the measured aerosol mass in several European suburban/urban sites, where f 60 was measured on average to be 0.028 in Roveredo, Switzerland , 0.02 in Grenoble, France (Favez et al, 2010), and slightly less than 0.02 in Augsburg, Germany (Elsasser et al, 2013).…”

“…The common marker for aged, oxidized organic aerosols is the peak at m/z 44, which corresponds to the CO + 2 fragment (Allan et al, 2004). m/z 44 correlates with the elemental oxygen / carbon ratio (O : C) (Aiken et al, 2007(Aiken et al, , 2008Canagaratna et al, 2015) and indicates organic aerosol aging (Ng et al, 2010;Cubison et al, 2011). A plot of f 44 (i.e., the ratio of m/z 44 to the total organic aerosol mass) versus f 60 for our study is shown along with Cubison and co-workers' previous data in Fig.…”

Response to Referee#1

“…Prior studies using an AMS instrument indicate that a potential marker of wood combustion is signalled at the massto-charge ratio (m/z) of 60, which is a major ion fragment present in spectra from the known biomass burning marker species, levoglucosan (Alfarra et al, 2007). The fraction of the organic mass spectrum that is at m/z 60 (termed f 60 ) is about 8 % in spectra from levoglucosan (Alfarra et al, 2007) and is often significantly larger than the background value of 0.3 % (or 0.003) for air masses that are influenced by biomass burning (Cubison et al, 2011). During wintertime evenings, wood combustion is known to be a major contributor to the measured aerosol mass in several European suburban/urban sites, where f 60 was measured on average to be 0.028 in Roveredo, Switzerland (Alfarra et al, 2007), 0.02 in Grenoble, France (Favez et al, 2010), and slightly less than 0.02 in Augsburg, Germany (Elsasser et al, 2013).…”

A Broadband Mid-Infrared Trace Gas Sensor Using Supercontinuum Light Source: Applications for Real-Time Quality Control for Fruit Storage

“…Nowadays, there are various types of detection methods that are at the frontier of trace gas sensing research [4,5,6,7,8]. In particular, MIR laser absorption spectroscopy provides a unique opportunity for fast, sensitive, and non-destructive detection [9,10].…”